Technical Field
The present invention relates to a situation comprehending apparatus, a situation comprehending method, and a program for situation comprehension.
Description of the Related Art
In general, an auto-focus function, in which an attention subject is automatically focused, is known in an imaging apparatus. For example, Japanese Patent Application Laid-open Publication No. 2013-160879 A discloses a technique relating to tracking movement of a subject and focusing the subject. Japanese Patent Application Laid-open Publication No. 2013-160879 A discloses an imaging apparatus comprising a region detecting means, a position change detecting means, and a determining means. The region detecting means calculates a feature quantity per feature in an image and detects at least two regions defined by the feature quantities. The position change detecting means detects positional changes at the at least two regions between frames. The determining means determines whether or not a distance to the subject has been changed based on a detection result provided by the position change detecting means. Japanese Patent Application Laid-open Publication No. 2013-160879 A discloses that, according to the technique, it is possible to predict whether a focusing direction is a front focus or a rear focus.
In the auto-focus operation, there is a situation in which it is difficult to obtain a focused state such as a backlight case and a case in which contrast of the subject is low. Even in such a case, quick auto-focusing is required. To achieve the quick auto-focusing, a distance to the subject needs to be obtained.
An object of the present invention is to provide a situation comprehending apparatus, a situation comprehending method, and a program for situation comprehension enabling a distance to a subject to be estimated in various situations.